Described by his neighbors as the quiet man next door, Mohammed Merah’s deeds shook the country and he boasted of having brought France “to its knees.” He said his only regret was that he was not able to kill more people, Paris prosecutor Francois Molins reported.

Adding to the fears in France that such attacks may be repeated it has been revealed that some 85 French nationals have undergone training in the Taliban’s Pakistan stronghold of North Waziristan in the past three years.

Pakistani intelligence officials say the French jihadists operate under the name Jihad-e-Islam and are trained to use explosives and other weapons at camps near the town of Miran Shah and the Datta Khel area, the Associated Press reports. They are led by a French commander who goes by the name Abu Tarek. Many of them have dual citizenship with France and North African countries. The officials added that five jihadists have returned to France to find new recruits.

In the wake of Merah’s attack, President Nicolas Sarkozy vowed to crack down on extremism. On Thursday he said that France would make it a crime to regularly visit terrorist websites. "From now on, any person who habitually consults websites that advocate terrorism or that call for hatred and violence will be prosecuted," Sarkozy said in a televised address. He also promised a crackdown on anyone who goes abroad "for the purposes of indoctrination in terrorist ideology.”

Merah is known to have spent time in Afghanistan and Pakistan and claimed that he trained with Al Qaeda. However a senior French official close to the investigation told the Associated Press there was no evidence he had "trained or been in contact with organized groups or jihadists."

Merah was under surveillance by French intelligence and his activities led to his inclusion on a US no-fly list. However this did not help to prevent the tragedy.